Permutation code printing receiver



T. I. miss PERMUTATION coma PRINTING RECEIVER Nov. 25, 1952- 5 Sheets-Sheet 2 Filed July 3, 1950 v INVENTOR. THOMAS I. R555 MGR AGENT Nov. 25, 1952 T. 1. R555 2,619,533

PERMUTATION coma PRINTING RECEIVER Filed July 5,1950 5 Sheets-Shet s ncmj noun;

DCIVE FIG. 4

INVENTOR. THOMASI RE 55 AGENT Nov. 25, 1952 T. l. RESS 2,619,533

PERMUTATION CODE PRINTING RECEIVER Filed July 3, 1950 I 5 Sheets-Sheet 4 FIGI RES 3 I I l 13136 i 1335 i g i FIG. 7 1546 i i l \l I L 3% 13134 INVENTOR. 1w mom/151'. R555 AGENT Nov. 25, 1952 T. 1. mass 7 2,519,533

PERMUTATION CODE PRINTING RECEIVER Filed July 5. 1950 5 Sheets-Sheet s an I! DD: an

Q g INVENTOR.

E 3 THOMASI. R555 Q FIG. 8

AGENT Patentecl Nov. 25, 1952 UNITED PATENT ore-Ice.

ERM TATIQ cons RINT ECE V Thomas I. Ress, Evanston, 111-.

Application July 3, 1950, SerialNo, 171,875

Claims.

inven on. r late t r n ng. receivers an -i morrn rt cullar to r nte s respo s ve i ttop sie as. eto. conven ional se e r e ghtunit ode ombination ba ed. n, a i r 9 ixeI men -n rmuta icm (Basi ode.

The advantages of facsimile reproduction or characters in response to suitable signals, e. g. bymeans of a printing helix co-operating with a carin u ace. q f convent na nt n e v'ers (using a v ew eel. r ty ars ha long been recognized. They reside, essentially, in; a considerable simplification of the receiving apparatus, by virtue of a substantial; reduction in the. nu e sep ate mova e c r s. h s in turn resulting in lower maintenance cost and decreased likelihood of mechanical failure.

"I has. l e ee r osed. o nc as h sp o ansm ss on in such s te s by p oviding at the transmitter selectable elements, one: foreach character to be transmitted, represen ns p rma n r ord o e'var u haracters. -to be transmitted, these records having been made. beforehand by what is termed a prens ra i or t ur ose. o r ducing, upon subsequent selective scanning, a train osii is s adapted to. control t eoperatio ofthe printing 'heligi after transmissionto the receivh s t n A disadv n e, f ch. a yst m, was as an y em. u in ire t scann s h e i. tr n it n lar e number ofv iil s r chec ata er th s a er a l 's c mment of transmission, as compared with characters transmitted in the. form. of a seveno s 'aisd' nd: o S nah mquem c ies'ffoig'corfiparable speeds. 7

Furthermore, precise synchronization between thev source of the pulse. trains and the. printing elements is. necessary to obtain an exact dTplica tion of the original signal; such synchroliaison over" appreciable distances. is difficult costly: to obtain, wherefore. it, has. heretofore beenycustomarv to use doublev helixes. for the purpose of minimizing the efiects of outso f-step scan ng by reproducing. each character twice, so a's-"todn's'ure, the appearance of at least one completecharacter. An arrangement of this description is, however, entirely. impractical for a page. printer since. the lines of each. page thus printed u -ould; be interspersed with fragments of haracter reatly d ctin r m. the ntelr li i ili vof he essa e- It is,. therefore, an important object of. my inventionto. provide an improved teleprinting receiver adapted to respond to permutation code cntfcode, r necessitating the; use,

2, Si nals. t r pr uc n th ch r te s com spondieg. to suc qqde' signals y cs m le p n mg.

More particularly, it is an object of this inven: tion to provide, in a teleprinting receiver, highly cient m s q tra a u t on code signals into pulse trains adapted to actuate a printing helix or similar facsimile reproducer.

Anot e b ect o h inv tio s t p ovi an ov d e e n r acc din to. t e t reeoins a a le. r u a a pa r n A. f r h ct o t e p e ent nven ion. i to provide means for so controlling the opera-' tion of the receiver that permutation code signals representing a character may be. received before the facsimile reproduction of the immediately preceding character has been completed,

It is also an object of this invention to provide, in a receiver of the character set forth, means responsive to shift signals (usually referred to as; letter shift and figure shift signals), in lieuof an additional permutation code element, so as to enable: substantially the number of char'-. acters transmittable with a six-element code to be reproduced with a five-element code, with the attendant increased speed of transmission and material reduction of receiving equipment as compared. withv systems utilizing the longer code.

With the above objects in view, and others that will subsequently appear, the invention a ccording. to one of its aspects provides, in a teleprinting: receiver, a distributor responsive to a combination code signal including a start cle QF EF pluralit o mmta on c de 1 1 an 5W9 e e t 1". of s l c or; ember equal innumber to the permutation code elements of the combination signal and selectively positionable, under the control of the distributor,

accordance with the nature. of respective permutation code elements, and a set of trackmembers each corresponding to a respective characterto be reproduced, these track members being individually selectable by. the positioning he se ect r members to odu r ns, of

- characteristic pulses adapted to. control the; 01?! eration of a f acsiniilereproducing device,

A r n o. mthea mo e sb fi as ct o the invention, the selection of a track; member is effected. by. Optical means; causing the. 'illumi nation of a selected; tra k m mb r a; eam of li ht. which is. mod a ed, b he. t ash memhe n t o. a h osens tiv dev ce, t rebvgiv ng-.- rs a ra n. Qt char ct ris c; u es adapted to neproduce. the character identified with such track member. The selective illumi- 7 3 nation of a track member may be effected by means of masks integral or operatively connected with respective selector members.

A desirable feature of the invention consists in the provision of a locking device arranged to maintain the selection of any track member effective until the arrival of the stop signal following the next permutation code combination and to cause a new selection to be made in response to such stop signal, the same signal initiating the scanning movement which produces the characteristic pulses under the control of the selected track member; such a locking device may be termed a memory unit, inasmuch as it preserves each code combination for utilization at a time subsequent to its actual transmittal.

According to another feature of the invention the set of track members is divided into two subgroups, each containing a number of track members equal to the number of selector members and respectively controlled thereby, the arrival of a shift or unshift signal causing one or the other group of track members to become effective to control the facsimile reproducing device.

The invention will be more fully described with reference to the accompanying drawing in which:

Fig. 1 is a diagrammatic view, partly in block form, of the general organization of a teleprinting receiver according to the invention;

4 Fi 2' is a more detailed view of the track selector system and the reproducing device controlled thereby;

Fig. 3 is a perspective view, on an enlarged scale, of the selector members, locking device and track system, together with the associated distributor;

Fig. 4 shows a set of selector members in the form of light masks, forming part of the system of Fig. 3;

Fig. 5 is a perspective view of a teleprinter similar to those shown in the preceding figures but adapted for use as a page printer;

, Fig. 6 is a side view of the printing helix used on the printer of Fig. 5;

Fig. 7 is a side view of a modified track cylinder;

Fig. 8 is a circuit arrangement of a modified form of printing receiver according to the invention;

, Fig. 9 shows schematically a further embodiment,v utilizing another form of optical track selection;

'Fig. 10is an enlarged schematic representation of the letter shift arrangement of Fig. 9;

and.

, Fig. 11 shows a modification of the system shown in Fig. 9.

Referring first to the schematic arrangement of Fig. 1, a line signal consisting of seven ele- :ments A G is fed to a distributor of a type known per se; this signal consists, in the .usual manner, of an invariable space impulse representing the start element, five code pulses B, C, D, Eand F (here given as the combination mark-space-mark-mark-space) and an invariable mark impulse representing the stop ele- 'ment. The distributor, which responds to the start element A, applies the code pulses B E over signal paths 21-25 to a selector unit 26 and the stop pulse G over a path 21 to a magnetic clutch 28 coupling the motor 29 to the transmission shaft 30. Pulses B F prepare the selector for operation under the control of a memory unit 3| which responds to the stop signal G, thereby causing a path 32 for the transmission of pulses to be completed through a facsimile signal generator 33. The generator in turn will produce a train of characteristic pulses which may be pulses of current or radiant energy adapted to be converted into pulses suitable to actuate the facsimile printer 34 and yield the desired printed message. The facsimile signal generator 33 and the facsimile printer 34 are mechanically coupled to transmission shaft 30 through gears 35, 36, respectively, and consequently operate in precise synchronism.

Reference is now made to Fig. 2 for a more detailed description of certain of the units shown in Fig. 1. The facsimile printer 34 is here shown to comprise a printing helix 31 mounted on the transmission shaft 30, on which shaft is also mounted a worm 38, meshing with a worm gear 35, and a pinion 39, meshing with a large gear 36 Gear 36 drives the roller 40 of a pair of feed rollers 4|], 4| between which passes the tape 42, the rollers and tape moving in synchronous relation to the movement of printing helix 31. Shaft 30 is coupled to the continuously rotating shaft 43 of the motor 29 by means of a magnetic clutch 28.

The worm gear 35 is mounted on a shaft to one end of which is fixed the hub 45 of a hollow drum 46 which comprises a major component of the facsimile signal generator 33. Mounted on the shaft 44 adjacent the gear 35 is a cam 41 which, near the end of each complete rotation cycle, bears upon a spring contact 48, thereby opening the energizing circuit for magnetic clutch 28, leading from battery 49 to ground.

On the periphery of the drum 4B are tracks 50, provided in the form of angularly spaced slots extending in circumferential direction. The slots are characterized by their transparency as contrasted with the body of the drum, hence they may constitute either physical apertures or merely transparent portions bounded by relatively opaque ones. Although only a relatively small number of tracks have been illustrated, for claritys sake, the number of tracks actually provided in the system illustrated, using a five-element Baudot code, will be of the order of sixty.

The tracks 50 are divided into two groups, each containing approximately half their number, to be referred to in the following as the letters and the figures group. Associated with both groups of tracks are an elongated source of light 5|, extending inside the drum 46 across the whole lengththereof, and a cylindrical lens' 52 p ositioned between the source and the selector mem} bers 26b, 26c, 26d, 26g and 26;, these members forming part of the selector unit 26. As will be more fully apparent from the subsequent discussion in connection with Figs. 3 and 4, the members 26 1 26] are characteristically apertured light masks whose apertures are staggered in such manner that in each relative position thereof the light from the source 5| will fall upon only one of the tracks 50 in each of the two groups of tracks, the two tracks so selected varying upon displacement of any one or more of these members from a normal" into a selected" position or vice versa. A single pair of light rays, indicated at 53' and 53", respectively, will thereby be directed upon two photocells 54, 54", which form electrical translating units for the letters and figures tracks, respectively; the rays pass through two parallel lens systems 55, 56 and 55", 56", each associated with a respecteases ti've.. 'o e of the two groups of. tracks; Either photocell may be conditioned for energization jover theconta'cts of a mechanically locking relay 8, coinprising in addition to armature 51 two windings 59' 59", energizable by way of leads I59 159", respectively, and an ogee spring 60 which cooperates with a pin 6| to lock the arma- "ture in either of two positions, depending on which winding is energized. Armature ener gization is selectively controlled by the system 26, in a manner shortly to be described. The cathodes of the photocells are grounded, the plate circuits being selectively connected over the armature?! through an amplifier B2 to a, counter electrode 63 opposite the printing helix 3], sufiicient space between the latter elements being provided to accommodate the moving tape 42.

liromtthe foregoing it will be apparent that certain signals, known as function signals, have .1 9 r k a c t t r w t Wher the. s stern is employed with a page printer in lieu of a tape recorder, these signals may include, in addition to letters and figures, such well-known function signals as line feed, carriage return, backspacing and so forth. Another signal for which no track need be provided is the spacing" signal which may be either a function signal, operating a contact switching system such as will be described in connection with Fig.3 for the purpose of causing advance of tape =32 without printing, or a signal causing the beam of light to fall upon a wholly opaque portion of the drum 1'46. a result, the number of tracks actually provided in each group will generally be some} what less than thirty-two. r

' Th tripping of clutch 2B is effected at the end of each incoming signal by means of the stop pulse G (Fig. 1) applied by the permutation code distributor 20 to the lead 21. This connects "ground to one side of the clutch, bypassing open contacts 48. Engagement of the clutch will effect rotation of the cam 41, allowing the spring contacts 48 to close and thereby establishing a connection to ground for substantially the remainder of the rotation cycle. At the close of the "cycle, the contacts will again be opened, disengaging the clutch and conditioning the circuit for subsequent closure by the next stop pulse. f, Assuming the relay 58 to be in the position illustrated, indicating the last shift signal received from the control system 26, 3! to have been of the letter shift type, the beam 53, mod fulate'd by a selected one of the tracks ill, will give rise to current pulses in the photocell 54' {which will be applied in the form of voltage pulsea'byway of the amplifier 62, to the counterfelectrode 63 associated with the printing helix :37, Since rotation of the helix is synchronized with the movements of the tape 42 by way of roller to, and also with the rotation of the trackcarrying drum 46, markings together constitut- "ing a printed character will be impressed upon the Sensitive ta e 42.

" Fig. 3 shows details of the light mask actuating and locking unit, or memory device, and ,the distributor 20. The light source El and the geylindrical lens 52 occupy, in relation to the drum 46 (not shown in Fig. 3), the positions shown in Fig.2, The energizing elements of the light inask actuating mechanism are fastened to a 'U-shaped frame which is located outside the drum '46. A bracket H is secured to the end of "the irame "i0 and extends into the drum 4s. Bracket ll contains sockets 72 (only one visible) "at each end for light source 51, above which 6 sockets are secured clamps I3 retaining the tynedrical lens 52. Af'clip M fastened to the bracket H holds the light source 5| in place. The'ligh't masks 26b 26, form a group of nested, inverted Us, the apertured sections extending along the bight of the'resp'ective Us and being yieldably supported by their vertical arms. one group of supporting arms are a set of leaf springs 15b 15 clamped in ablo'ck 15 to the bracket ll at the end farthest from the frame 10, the arms being suificiently spaced to allow a small amount of free horizontal movement. The other group of vertical arms form leaf springs, such as 16f, pi'votallysec'ur'ed by a pin 11') to a plate amouiitedon the back or the name is. A iever arm 19 pivoted about a pin '80 projecting from the frame llLis urged in a clockwise direction byda s'pring Bl) fastened to the frame T0 and engages the leaf spring 16 at a point near, its junction with'the horizontal section of the light mask 26 An L"-sha'ped 'do'g 82] is also fastened to the leaf spring 76], the horizontal portion thereof bearing on an edge of a notch 83f which is one of five notches 83b car out in the top edge of the plate 78. The vertical portion of the dog '82) fits into either of a pair of adjacent notches EM and SM", out man edge of 'a plate hingedly connected to the plate Ill and ex te'jndi'ng at right angles thereto; notches 84b 84f correspond to the normal "and notches 84b" 84'1" to the selected portion or the associated seieotoririembers 26b is). As shown, the member 26 is iiormei, it's oo'gt'zj being engaged by the notch 84f" corresponding thereto. A solenoid 86, spaced a short distance from the plate 85, acts to pivot the plate 'abbu't its hinge, thus freeing the dog 82 from the notch 84f and allowing the spring 16] to follow counterclockwise rotation of the lever arm 19f. A leaf spring 81, f xed to the solenoid support, ieturns the plate 85 to its original position upon de-e'n'ergization of the solenoid. A movable arm 91 of a spring contact assembly is fixed to the end of the dog 82f, this arm causing a tongue .981 selectivelyto engage "either of the contacts 99f, 99f" depending upon the position of dog 82f.

A second solenoid 88 is mounted on an angle bracket 89 secured in turn to the frame 10, the solenoid facing the lever arm 19] below its pivot and acting to urge it into counterclockwise motion upon energization. The lever arm '19) terminates in a finger 9E1 which bears upon "a spring 9| 1, the latter being one of five springs 9lb 9H mounted on at bar 92 extendin along the length of the frame and pivoted there to. A dog 93, fixed to the axle of the bar 92 and to a biasing spring $5, cooperates with a stop 94 to limit the angle through which the bar 92 may turn. Energization of the solenoid 88;

causes the finger 96 of the lever arm 19 to swing past the spring 9| which thereupon latches it in selected position; the lever arm may be released by the energization of a third solenoid 96 which 'acts to pivot the bar 92 against the action of spring 95, causing the spring 9|)" to is connected to the Stop segment of the distributor, second solenoid 38f i's'c'onnec'ted to segment of the distributor (segments I through 4 of the distributor will in like manner be connected to associated solenoids not shown), third solenoid 96 is connected to the Start segment of the distributor; each of the solenoids is grounded at one end. Battery is permanently connected to segment I03 of the distributor, which is associated with the Stop" segment, while segments I04 and I65, associated respectively with the Start segment and with segments I through 5, are selectively connected to battery over armature I02. A solenoid I06, grounded at one end, is connected to the Start segment and acts to attract a latch I01 to permit movement of the distributor arm I08 upon receipt of a spacing" pulse, representing the start element of a code signal, over the line.

The condition illustrated in Fig. 3 indicates a period during which no signal is being transmitted. The relay IOI is continuously energized by a steady closed-line (or marking) condition. The system is prepared for the receipt of a message by the starting element thereof which de-energizes the relay I02, connecting battery to the Start segment, thus energizing the solenoid I05 and displacing the latch I01 to release the distributor arm I08 for a single revolution. At the same time the solenoid 93 is energized, causing the bar 02 to turn and freeing lever arms such as 19 from associated locking springs Slb 9| if previously engaged thereby. The distributor arm continues to rotate, passing the Start segment, thus de-energizing solenoids I06 and 9S and thereby allowing latch I01 and bar 02 to resume their former positions. Subsequent marking signals will energize the relay IOI and, through synchronization with the distributor arm in a manner well-known in the art, produce voltages at the terminals of selected ones of segments I 5. These voltages will serve to energize solenoids such as 88 which will rotate the lever arm 19] counterclockwise. Although any substantial displacement of the associated selector member 28 is temporarily prevented by the engagement with notch 84" of the dog 82, the lever arm i9 is free to rotate about its pivot 80] until the finger 90 thereof has cleared the locking spring em. Continued rotation of the distributor arm I08 brings it to bear upon the Stop segment, energizing solenoid 86 which in turn causes plate 85 to pivot, momentarily freeing the dogs such as 821 from the associated notches, such as 841. The leaf springs 18 are so biased as to force the associated light mask 26f to the left. The positions of the remaining light masks will similarly be determined at this instant by the position previously occupied by the associated lever arms. Simultaneously, the clutch 23 (Fig. 2) will be energized over lead 21, effecting entrainment of the drum 46 and printing helix 3? as already described. As the distributor arm leaves the Stop segment the solenoid 88 will be de-energized and the notched plate 85 will fall back into position, locking the light masks in place. The distributor arm continues to the Start segment, again energizing the solenoid 96 and thus freeing the lever arms such as 79f from their associated locking springs such as S I 1. Further movement of the distributor arm is prevented by stop arm I01 until a new code signal is received, at which time the foregoing procedure is repeated.

It will thus be seen that printing of a character corresponding to any code combination received will take place during a period following the completed reception of such combination; since the resetting of the selector members (light masks) is virtually instantaneous, there is thus made available for character reproduction a time interval equal to almost a full signaling cycle, so that a subsequent code combination may already be received and registered (by means of the lower arms such as 19f) while the printing of the preceding character is still in progress.

Fig. 4 illustrates the light masks 26b 26 and shows the relative positioning of their aper tures. It will be noted that each mask is provicled with two identical series of apertures, so that two rays (for selection of a character from the letters and figures group, respectively) may pass in each of the 32 different relative positions of the masks.

Shifting and other functions are controlled by the set of contacts 98 99 99f conjointly with similar contacts associated with the other selector members, these contacts effecting the selective closure of several control circuits in certain relative positions of the selector member. Thus it will be seen that leads I, I59, leading to the windings of the shift relay 58 (Fig. 2), have been shown connected to contacts 09 and 091", respectively. It may be mentioned that some or all of these functions may also be carried out with the aid of special photocells, as indicated at I58 (Fig. 4), positioned to receive light only in certain relative positions of the light masks.

Figs. 5, 6 and 7 show a page printing apparatus utilizing the principles underlying the foregoing embodiment. Fig. 5 shows a perspective view of the apparatus, including a transmitting keyboard which operates in cooperation with a conventional seven element code distributing system; the transmitting section may be coupled to the receiver, presently to be described, so that the operator may have a record of the page as it is printed.

As shown in Fig. 5, the page printer presents a picture somewhat similar to a conventional typewriter, having a keyboard 2I0, a movable platen 263 and a printing element, the printing helix 231, adjacent the carriage. The actuating mech anisms are powered by a motor 229, to the shaft of which is secured a worm 2| I. The worm mates with a worm gear 2I2 mounted on a shaft 243, this shaft terminating in magnetic clutches 228', 228", one on each end thereof. Shafts 230, 230" are coupled to the clutches 228, 228", respectively, for entrainment by the shaft 243 upon energization of the respective clutch. Shaft 230" carries a gear 238 which mates with another gear 235 and through the latter is coupled to a cylindrical drum 246. The drum is seated on two pairs of rollers 2I3 rotatably secured to the base of the printer housing. Mounted at the end of the shaft 230" is a pinion 230 which mates with a gear 240, the latter driving a helically threaded spindle 2I4 which engages a mating nut (not shown) inside housing 234 of the printing helix. The housing rides on a grooved shaft 2I5, extending parallel to shaft 2M, which terminates in a gear 236 coupled to the gear 240. The shaft 2I5 controls the turning of the printing helix 23?; thus the printing helix and the drum are again synchronized. In order to conform to the cylindrical shape of the platen 263, the printing helix 231, as best seen in Fig. 6, will be of an hour-glass shape so as to maintain a fixed spatial relationship with the surface of the paper 203 over the full height of each line of print.

.This unique features assures unform marking intensity over the entire printing-area.

. The other magnetic clutch 228' carries a shaft .230 on which is mounted a worm 2 I 6 which mates with a worm gear 2I1 and is coupled by way of transmission means 2| 8 to a pinion 2I9 which mates with a gear 220 secured to the platen; the mechanism just described performs a line feeding operation in response to a suitable function signal which energizes the clutch 228. Carriage feed is effected by means of the cord 22I, wound upon a spring-biased reel inside a box 222, the return of the carriage in response to a corresponding signal being accomplished by suitable mechanism not further illustrated because wellknown per se.

-A modified form of track-carrying drum is illustrated in Fig. 7. Bearing upon the outer surface of the drum I346 are four rollers I3I3a l3l3d, tangent to the drum at points 90 apart. A roller I 3 I31) bears on the inner surface of the drumopposite the roller I3I3b. The drum is driven by a sprocket wheel I335, mounted on the inside of the drum opposite roller I 3 I 3c. With this arrangement, wobbling of the drum is prevented, the drum moving evenly between the rollers.

v The drum I346 ispreferably made of lightweight material, such as a celluloid film to which the several tracks are applied by photographic means. Such a drum; has a very low moment of inertia, thus enabling rapid starting and stoppingof the reproducing mechanism.

Fig. 8 shows another embodiment of the invention in which a system of relays is, used in lieu .of the light masks of the previous figures. The conventional Baudot distributor arranges inent. previously described in connection with Fig. 3 here reproduced for better understanding of the figure. Elements IIlI, I02, I06, I61,"and I26 of Fig. 3 are labeled 36L 302, etc. in the present figure and need not'be further described. In Fig. 8, however, there is connected in parallel with solenoid 306 a relay 325 connecting ground. in its de-energized position, to the windings of five preselecting relays 32Gb 326}. The othersides of the aforementioned windings are connected to the segments of the Baudot distributor respectively numbered I through 5, and are also connected to respective holding arma tures such as 32Ib. A locking circuitto battery and ground is provided over the front contacts associated with the aforementionedarmatures. A second set of armatures such as 3295 are connected to the armature 381 of aswitch-over relay 385, the front contacts ofarmatures 329D I etc. being connected to the grounded windings of respective selector relays33lbf. .33. The selector relays 33H) 33If are each provided with a holding armature such as 3301), one or more character selecting armatures such as 33% and one or more function selecting armatures such as 336?). Holding armatures 3301) etc. are normally connected to battery via the back contacts associated with armature 381 of relay 386. Relay 386 is connected to the Stop segment ofthe Baudot distributor, thus being energized only during the time the distributor arm thereof sweeps over this segment. The character selection armatures 3351; etc. of relays 33Ib 33h, which are in series with the printer 334, increase in number according to a binary law, relay 33Ib having one selection armature, relay 33Ic-having two and relay 33If having sixteen. The func-v tion selection armatures 3361) etc. of ,theserelays also increase in number, but to a less extent depending upon the number of functions to be performed; among the circuits selectively closed by the latter are those of shift relay 358, includ: ing leads 359" and 359".

Two sets of conductors 332, 332", connected in parallel to the front and back contacts associated with the character selection armatures of relay 33H, lead to brushes 331', 331 which bear against the tracks 356', 350-" on drums 346, 3.46". The tracks consist of insulated strips which cover the conductive drums, thus the brushes will bear against the conductive surface at spaced intervals. The armature 35'! of shift relay 358 selectively connects battery to drum 350', the Letters drum, or drum 356", the Figures drum.

- The operation of the relay system is analogous to that of the light mask system. Again the Baudot arm is released by latch 30'! upon recepe tion of a spacing pulse over the line. Subsequent marking pulses will connect battery to certain of the segments I through 5 over line relay con: tact arm 362; the voltage will be transmitted to the associated preselecting relays such as relay 32622 which will lock over armature 32m to ground on the armature of normally de-energized relay 325. When the distributor arm reaches the Stop segment, relay 386 will operate and, over its make-before-break contact, will connect bat.- tery to the winding of any selector relay associated with a locked preselecting relay before re-. moving battery from the holding circuits of all the selector relays previously operated. As soon as the arm leaves the Stop segment, relay 385 will be de-energized, yet the holding circuit for relays 33Ib 33If will be closed before battery is removed from their operating circuits ex-. tending through armature 3291; etc. Thus the selector relays. will remain selectively operated, in accordance with the combination previously received, while the preselecting relays are being reset by the subsequently arriving code pulses, their own circuits having been broken upon are rival of the start impulse preceding the next code combination.

Assuming the relay 358 to be in the position shown, the Letters" drum 350' will be connected to battery and a voltage between the facsimile printer 354 and the drum will be gen-, erated. Current will fiow'through the facsimile printer whenever the brush 337 bears against the conductive drum; this current may be used to produce a voltage which may be applied to a printing helix and counter-electrode assembly as shown in the preceding figures.

In Figs. 9 and 10 another modification of the invention is shown whereby selective rotation offive mirrors serves to deflect a beam of incident light into any of 32 positions. Five solenoids 42Gb 426 serve as the actuating mechanism for five associated mirrors 43Ib 43h, re-.- spectively, the energizing voltage being supplied by a Baudot distributor (not shown) operating in the same fashion as previously described. A

beam of light 453 is produced by a light source 45I and is brought to a focusby a converging lens 452. A portion of the resultant beam is pere mitted to pass through a mask 455 having a pin-. hole 455a placed a little beyond the focus, as best seen in Fig. 10. Two solenoids 459', 459", operating under the control of systems analogous to those shown in connection with shift relay wind.- ings 59, 56", selectively displace the screen a1- lowing eithenthe top or the bottom portions of the beam of light to pass through the opening. A second converging lens 456 now directs toward a remote focal point the resultant beam, the focal length of the lens 456 somewhat exceeding the overall length of the light path on its way to the surface of drum 446. As shown in Fig. 10, movement of the pinhole will have the effect of cutting on different, slightly overlapping portions of the beam, so that the locus of impingement of the light rays will appear some what displaced. This apparent displacement should correspond to about half the unit of displacement obtainable through movement of the mirrors (i. e. the displacement obtainable by moving the last mirror 43I through energization of the associated solenoid 426 by alternating Letters and Figures tracks on the surf-ace of drum 446, the desired shifting operation may be performed in simple manner by an almost infinitesimal displacement of the mask 455.

It should be understood that, for the purpose of obtaining the proper increments of displacement with the mirrors shown, their distances from the surfaces of the drum (measured along the path of light) should increase according to a binary law or else their angles of displacement should be suitably staggered. Furthermore, the spacing between the drum and the last mirror 43!/ should be so large that the beam need only to swing through a very small angle in sweeping from one end of the drum to the other, unless other pre cautions (as by curving the outer surface of the drum) are taken to insure that the length of its path remains essentially the same for all positions of the beam.

Fig. 11 shows part of an optical selector system similar to that of Fig. 9, except that the mirrors 53H), 53lc (only two shown) are now displaced parallel to themselves rather than about a pivot. In order to dispense with the need for staggering the extent of displacement of successive mirrors, converging lenses 551, 558 have been inserted therebetween, the focal length of the first lens 551 being half that of the second len 558. As a result of this arrangement, a displacement of the beam due to movement of the mirror 53th will manifest itself at the mirror 53lc in a displacement of twice the original magnitude, this magnitude being further doubled at each successive mirror. Selective movement of the five mirrors of the system will, therefore, again result in 32 different end positions of the beam. It will also be noted that with this arrangement the overall length of the light path remains substantially the same for all positions of the beam.

The various embodiments of the invention herein disclosed lend themselves to the control of a large variety of reproducing devices utilizing voltage, heat, ink, light, pressure or other forms of energy for marking a sensitive blank. The reproducing device need not be a helix but may, for example, take the form of a disk having projections on its face spaced along a portion of a spiral, similar to the apertures of a Nipkov disk, which projections successively scan different portions of the area to be printed. Moreover, the conventional platen shown in Fig. may be replaced by a vertical cylinder, havin its axis parallel to that of the printing helix, in which case the latter need not have hourglass shape but may be of cylindrical configuration; also, such a vertical platen might be used in combination with a disk having a spiral ridge on its face, this ridge scanning the printing area along vertical lines in 12 essentially the same manner as does the helical ridge of the scanning element 23'! (Figs. 5 and 6).

Finally it may be mentioned that the invention is not limited to the reproduction of characters from elongated tracks having alternating light and dark areas in linear succession. Thus it will be possible to employ, instead, track members of, say, square or rectangular configuration, each carrying a respective letter or figure, which may be traversed or impinged upon by a beam executing an area scanning movement so as to produce a pulsating output adapted to be applied to the reproducing device at the printer. Various other modifications and adaptations will be readily apparent to persons skilled in the art and are intended to be embraced in the scope of the invention as defined in the objects and in the appended claims.

I claim:

1. In a printing receiver, in combination, a source of light, first focusing means forming said light into a converging beam, second focusing means positioned back of the focal point of said first focusing means and causing said beam to converge at a remote point, a receiving surface adjacent said remote point, masking means adjacent said focal point displaceable to cut on" different portions of said beam, thereby obliterating diiierent portions of the image projected by said beam upon said receiving surface, signal-responsive shift means controlling the position of said masking means, and signal-responsive deflecting means in the path of said beam for selectively displacing the image projected upon said receiving surface.

2. In a printing receiver, the combination according to claim 1 wherein said deflecting means include a set of mirrors positioned back of said second focusing means, said mirrors directing said beam upon said receiving surface over a circuitous path, and signal-responsive control means for selectively displacing said mirrors.

3. In a printing receiver, in combination, a permutation code distributor, a plurality of track members of varying optical permeability, said track members being divided into groups, a source of light producing a beam of light, optical defleeting means between said source and said track members adapted to change the direction of said beam of light for selectively aligning said beam with difierent ones of said track members, selector means connected to said permutation code distributor and operatively linked with said optical deflecting means for controlling the position of said beam in response to code signals received by said distributor, switch-over means controlled by said selector means for limiting the positions of said beam to alignment with track members of a selected group only, said selector means actuating said switch-over means in response to predetermined code signals for changing the group thus selected, scanning means for relatively displacing the selected track member and said source of light, thereby modulating said beam, and output means in the path of the modulated beam and responsive to the modulation thereof.

4. In a printing receiver, the combination according to claim 3 wherein track members of different groups alternate, the minimum displacement of said beam due to said control means corresponding to the minimum distance between elements of the same group, said switch-over means displacing said beam by a fraction of said distance.

5. In a printing receiver, in combination, a permutation code distributor, light source means at a first location, photosensitive means at a second location, a pair of photoelectric translators each including part of said light source means, part of said photosensitive means and a respective group of track members of varying optical permeability between said light source means and said photosensitive means, switch means at one of said locations controllable by said permutation code distributor for selectively inactivating either of said photoelectric translators in response to a shift signal received by said distributor, selector means intermediate said locations common to both of said photoelectric translators and controllable by said permutation code distributor for directing light from said light source means onto a selected track member of either group in response to a code signal received by said distributor, scanning 14 means for relatively displacing said selected track member and said light source means, thereby producing a modulated light beam impinging upon said photosensitive means, and electric signal generator means connected to said photosensitive means for producing an output varying with the modulation of said beam.

THOMAS I. RESS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,988,409 Amann et al Jan. 15, 1935 2,327,369 Potts Aug. 24, 1943 2,334,234 Zenner Nov. 16, 1943 2,494,296 Springer Jan. 24, 1950 

